Effects of different sutures on fibrosis and wound healing in a rabbit model of corneal wounds

Abstract

The aim of the study was to investigate wound healing and scar formation in rabbit corneal lamellar wounds repaired with simple interrupted sutures (SIS) or horizontal mattress sutures (HMS). Two parallel ‘I’-shaped lamellar cornea wounds were created in one eye of 40 white New Zealand rabbits, while 5 uninjured rabbits were sacrificed to serve as normal controls. One side of the wounds, in the test rabbits, was closed with SIS, while the other side was treated with HMS. Ten days later, the stitches were removed under anesthesia. The animals were sacrificed on days 14 and 21, and months 3 and 6 after the suturing surgery, and corneal samples were subjected to histological and immunofluorescent studies: α-smooth muscle actin (α-SMA) and vimentin were used to detect myofibroblasts and fibroblasts, respectively, and collagen type I and Ⅲ was used to detect extracellular matrix (ECM) deposition. Relevant mRNA levels were assessed by quantitative polymerase chain reaction (qPCR) to elucidate the differences in wound healing and formation of fibrosis. Macroscopic and hematoxylin and eosin staining observations showed that the two sides of the wounds developed the most prominent fibrotic tissue on day 21. The immunofluorescence and qPCR results showed that HMS wounds produced increased α-SMA, vimentin and collagen type Ⅲ compared to the SIS wounds on day 14 or 21. The collagen type I expression showed no distinctive difference in SIS and HMS wounds. In conclusion, corneal lamellar wounds treated with SIS developed less fibrotic-related proteins and related mRNA in the early stages of wound healing than wounds treated with HMS. Although differences were not distinct after 3 months, the results of the present study suggest a benefit in choosing SIS over HMS, as at least the initial fibrotic process seems more benign with SIS. Corneal wounds should be carefully sutured, ensuring the tissue is well aligned.